|Lead PIs||Rhett Jackson, (UGA), Chelcy Ford Miniat (USDA Forest Service)|
|Co-PIs||C. Pringle, N. Heynen, P. Bolstad, N. Wurzburger, J. Clark, J. Mohan, J. Maerz, C. Dehring, M. Turner. S. Pearson, F. Benfield and others|
|Graduate Students||Susan Dye (MS), Maura Dudley (current PhD student), John Frisch (MS), John Kominoski (PhD), Natalie Powell (MS), Kate Schofield (PhD), Kelsey Solomon (current PhD student), Jeremy Sullivan (current PhD student)|
The Coweeta Long-Term Ecological Research (LTER) Project is based out of the Coweeta Hydrological Laboratory (2185 ha) located in the Nantahala National Forest of the southern Appalachians. The Coweeta LTER was first funded in 1980 and is one of the six original sites in the US LTER network. It is based on a collaborative agreement between the University of Georgia in Athens, Georgia, and the USDA Forest Service Coweeta Hydrologic Laboratory in North Carolina.
History of our research involvement: Our lab became involved in the Coweeta LTER Project in the mid-1990s as part of an LTER Regionalization Addendum designed to expand field research to regions outside of the Coweeta Hydrologic Laboratory. Our initial research was in collaboration with Judy Meyer’s lab and focused on the effects of increased sedimentation on algal- and detrital-based stream foodwebs in the southern Appalachians (e.g., Schofield et al. 2004). We also examined how land-use change affects stream trophic dynamics (i.e. the top-down effects of stream macroconsumers (fish and crayfish) along forested to urban land-use gradients (Schofield et al. 2008). These afore-mentioned studies were based on in situ stream experiments. We also became involved in long-term (30 yr) stream monitoring efforts to link ecological changes in streams with changes in land use (Gardiner et al. 2009). We are still involved in this ongoing effort which has been coined the Coweeta Hazard Site Project (see section below). In 2000, our research focus shifted to address the question of how changes in leaf litter species diversity affects decomposition dynamics, again through in situ experimental studies in streams (e.g., Kominoski et al. 2007, Kominoski & Pringle 2009, Kominoski et al. 2009).
Current Research – Coweeta LTER VII: The interacting effects of hydroclimate variability and landscape modification in the southern Appalachian Mountains. Southern Appalachian forests are among the most highly diverse temperate ecosystems, yet they are vulnerable to rapid exurbanization and increased hydroclimatic variability (e.g., prolonged droughts) associated with climate change. Our lab is presently involved in the ongoing studies described below:
1. The Coweeta Hazard Site Project: Landscapes in the rapidly exurbanizing southern Appalachian region are expected to undergo dramatic changes in land use over the next 50 years due to increasing human populations. The goal of the Coweeta Hazard Site Project is to examine how the ecological characteristics of stream ecosystems change in response to development. The project is based on a 30-year (2000-2030), proactive sampling strategy, whereby 8 headwater streams and their associated sub-watersheds (N=2 forested reference sites, N=3 urbanizing sites, and N=3 exurbanizing sites) are sampled every five years for physical, chemical and biological (algae, macroinvertebrate, and fish) attributes. At the onset of the project, a predictive landuse/land change model (Wear and Bolstad 1998) was used to identify sub-watersheds that were either likely to undergo substantial development along two landscape trajectories (forested to low-density mountain-side development or agricultural to suburban) or unlikely to undergo any development. In year 1 (2000), Gardiner et al (2009) found broad differences in water chemistry, geomorphology, and biota between streams in forested, exurbanizing, and suburbanizing sub-watersheds. Based on these initial results, he predicted that streams in forested, exurbanizing, and suburbanizing sub-watersheds would support streams with diverging biotic communities and physical conditions over time. As part of his dissertation research, PhD student, Jeremy Sullivan is analyzing data from the 2005 and 2010 sampling events to assess potential ecological effects of land use change, ten years into this thirty-year study.
2. The Southern Appalachian Stream Visual Assessment Protocol (saSVAP): We have developed a stream visual assessment tool for the southern Appalachian region. This tool is a customized adaptation of the Stream Visual Assessment Protocol (SVAP), initially co-developed by our lab at UGA with the USDA Natural Resource Conservation Service (NRCS). The new protocol is called the Southern Appalachian Stream Visual Assessment Protocol (saSVAP) for assessment of wadable streams within the Blue Ridge eco-region. PhD student, Jeremy Sullivan, took the lead in developing saSVAP to rapidly evaluate stream habitat conditions and educate local residents about ecologically relevant characteristics of stream integrity. By providing citizens with this stream assessment tool, our goal is to improve the awareness of residents in southern Appalachia of the important services streams provide and to increase the geographic scale and frequency of stream assessments. Accordingly, the saSVAP is being implemented by the Little Tennesseee Land Trust in collaboration with the Coweeta LTER and graduate students within the University of Georgia’s Integrative Conservation (ICON) PhD Program.
3. Riparian Rhododendron Removal Experiments: We are beginning collaborative studies to examine stream ecosystem response to large-scale removal of rhododendron riparian vegetation. The historic loss of chestnut (from a fungal disease) combined with the more recent loss of the eastern hemlock (from the woolly adelgid) has resulted in expanding Rhododendron which inhibits the recruitment of upperstory hardwood species. The Forest Service is implementing large-scale experimental removal of rhododendron in riparian corridors once dominated by eastern hemlock into which rhododendron has since expanded. The extensive treatments will consist of four, 300-m reaches on 2nd and 3rd order perennial streams between 670-1000 m elevation. Stream measurements will be overlapped with terrestrial measurements to identify cascading effects on ecosystem properties and processes within and between water and land. Our lab is assessing how different rhododendron removal treatments affect algal standing crop, nutrient uptake, respiration, and stream trophic dynamics. PhD student, Maura Dudley, is focusing on this for her dissertation research.